Problems in Design of Reinforced Concrete Structures
1. unreasonable structure system
In the design of reinforced concrete structures, designers need to choose a reasonable structure system according to the characteristics of Engineering structures, seismic grade and wind load. However, if the selected structural system is not reasonable, it will affect the stability of the structure and reduce its structural performance. If the design indicators chosen by the designers are not scientific, it will also reduce the feasibility and scientificity of the structural design, resulting in problems in building quality and even lead to safety accidents.
2. Problems in the design of substructure
(1) Basement floor design. Because of the load on the superstructure of the building, the settlement and deformation of the independent foundation under the column and the roof of the basement occur. If we do not pay enough attention to this situation in design, it will cause the basement roof to bear too much pressure, and it will easily break after exceeding the limit, leading to the inclination of the building and even structural fracture. (2) The reinforcement of basement floor is unreasonable. Basement, as a part of infrastructure, can not only enhance the stability and bearing capacity of building structure, but also reduce the degree of earthquake damage. In basement design, unreasonable reinforcement of basement floor will lead to instability of reinforced concrete structures and increase the uneven settlement of buildings. (3) The design of natural foundation is unreasonable. In the design of independent foundation in natural foundation, unreasonable design is adopted. The slope is more than 1:3, which makes the vibration of foundation concrete not compact, affects the quality of vibration, and affects the stability of foundation structure. In the actual construction process, manual vibration is often used to vibrate concrete, but the quality of vibration is not easy to control, or even can not meet the design strength requirements. (4) The influence of groundwater level. In the design of reinforced concrete structure, the influence of groundwater level has a great influence on the stability of its structure. In the design process, special attention should be paid to the place where the groundwater level changes greatly, and attention should be paid to the waterproof and dewatering of buildings, which plays an important role in the construction progress and quality control of construction projects. At the same time, in the design of the whole building foundation structure, the foundation is subjected to the load of the superstructure. Once the settlement changes, the basement roof and the pillar will bear the force together.
Problems in Superstructure Design
In the design of reinforced concrete structures, the theory of superstructure is relatively mature and the existing problems are relatively few, which are mainly reflected in three aspects: first, if the design of frame shear wall is unreasonable, it will lead to more concentrated stress and threaten the safety of the building structure. When earthquake occurs, the building structure is prone to collapse. The uneven distribution of shear walls will also increase the difficulty in the design of frame-shear wall connections, which is not conducive to the stability and reliability of building structures. Secondly, in the building with reinforced concrete structure as the main component, the most important component to resist lateral force is reinforced concrete. Therefore, the measured displacement of reinforced concrete structure must meet the prescribed lateral displacement limit. If it exceeds the limit, the stability and safety of the building structure will be affected. Finally, the problem of cracks is an important part in reinforced concrete engineering, which can be divided into structural cracks and structural cracks. The structural cracks are caused by improper or non-standard operation of construction technicians, such as inadequate vibration of concrete, unreasonable water-cement ratio, inadequate maintenance, change of template position or premature demoulding. The structural cracks occur in the pouring process of reinforced concrete structure, which is due to the stiffness difference between different components, forming a weak stiffness area, resulting in cracks in the structure, often at the top of the floor or corner.
Existing Problems in Seismic Design of 4 Structures
In the design of reinforced concrete structures, the seismic performance grade of structures must be considered, which is of great significance to the safety of buildings. Earthquakes are common natural disasters, which affect the structure of buildings from the inside to the outside. The longitudinal wave of earthquakes exerts a force on the structure of buildings, resulting in changes in the appearance of solid structures such as loosening, cracks and so on, which seriously threatens the stability of building structures. Although China is not a country with frequent earthquakes, the occurrence of several major earthquake disasters in recent years and past experience also show that buildings with high seismic grade have relatively high stability and safety in earthquakes. Therefore, improving the seismic performance of buildings is the focus of current attention. Because of the characteristics of reinforced concrete structure itself, its seismic performance is low, which is also a key problem to be solved at present.